Percutaneous placement of intravascular catheters, pacemaker leads, etc. involves blood loss that, while easily controllable especially during venous access, can become significant during long procedures. For example, procedures such as placement of leads in the coronary sinus for biventricular pacing, can last 4 hours, during which time the blood loss of up to 500-600 cc can represent a risk to the patient. Additionally, the open conduit into the body can become a source of infection to the patient. To help reduce these potential risks, self-sealing hemostatic valves have been developed for use with introducer sheaths. These valves provide a seal against flashback of blood from the proximal end of the sheath, including when a second device is being manipulated within the introducer.
Medical devices with large proximal fittings, such as pacemaker leads and PICC lines, cannot be readily used through standard hemostasis valves and introducers because of the need to remove the introducer while leaving the other device in place. To address this need, splittable sheaths and hemostasis valves were developed so that the introducer and valve can be removed while the inner device remains in the patient. Combinational devices exist, such as the SAFE-SHEATH™ Splittable Valved Sheath System (Pressure Products, Inc., Rancho Palos Verdes, Calif.), which is comprised of a splittable valve attached to the end of a scored introducer sheath. The valve housing containing the valve membrane is split along scores lines, which are aligned with score lines that continue down the length of the integral introducer. Thus, the valve and introducer are split together. One disadvantage of this combinational system is the lack of flexibility in how the device is used. For example, to place a coronary sinus pacemaker lead, a physician will often wish to advance the long introducer sheath into the coronary vessel, then partially withdraw the sheath, perhaps 10 cm, prior to introducing the pacing lead. The large integral valve at the proximal end of the sheath cannot enter the patient, therefore, the physician must have an undesirably long section of introducer exiting the patient, where ideally, he or she would like to peel the introducer back closer to the entry site. In addition, the scored introducer portion of the SAFE-SHEATH™ lacks the structural integrity to negotiate tortuous bends of the coronary vessels. Because the valve and introducer are designed only to be used together, the system cannot be adapted to work with different sheaths and other intravascular devices that may offer important clinical advantages in certain procedures.
Furthermore, while a valve body shell may provide an adequate barrier against fluid backflow when used in the venous system where pressures typically average around 0.2 psi, arterial pressures represent over a ten fold increase over that of the venous side, making sealing much more difficult.
What is needed is a simple system that provides a platform to introduce materials to the body and offers quick dissembling capabilities. It is desirable to have a valve that can provide superior sealing characteristics, especially in the presence of high backflow pressures such as seen in arterial applications. It is also desirable to prevent leakage of fluids and/or reduce exposure to air-borne pathogenic organisms. Further considerations include having a splittable hemostatic valve of simple construction that is easy to use, functional and inexpensive to manufacture.